"I'm a bit of a bad boy," the actor said. He then demurred, "by the way, I'm still not sure my hand was really on her butt. I think that's just the way the camera was angled," before breaking into laughter. "I actually haven't seen [the photo]."

The star also continued to deny any romantic involvement with Aniston, 41. "If I was going out with Jennifer, I'd be more than happy to say I'm going out with Jennifer -- it's just not true."

Yet a Butler pal counters in the new Us Weekly that the flirty costars have been "hooking up for a while." Another source confirms that the pair slept together during her February birthday blowout in Mexico.